ghci: can't load module BitSet, and some others

Hi. I'm totally puzzled: ghc-pkg describe ghc shows BitSet as exposed module. When grepping the whole ghc source code the only occurance I can find is in the package.in file for the ghc package. But that't it Trying to load it using GHC-api or ghci fails ? Is this module depreceated and only there for compatibility reasons? darcs changes reveals: Wed Oct 11 15:16:14 CEST 2006 Simon Marlow <simonmar@microsoft.com> * remove BitSet, it isn't used So is it time to remove it completely? I can't load all these modules: BitSet FieldLabel IlxGen Java JavaGen PrintJava RegisterAlloc So what's wrong here? Sincerly MarcWeber